António Augusto Carvalho Monteiro, known as the Millionaire, bought the land in 1892 and hired the Italian architect Luigi Manini. Construction began in 1904 and was largely complete by 1910. The article calls the palace Romantic, and says Manini evoked Roman, Gothic, Renaissance and Manueline styles. The facade is Gothic, with pinnacles, gargoyles and an octagonal tower. It has five floors on an estate of about four hectares.
The Initiation Well is 89 feet (27 m) deep, with a spiral staircase of nine flights, and the park has a network of underground tunnels. The article does not state the main construction materials.
Sintra Town Council acquired it in 1997 after a Japanese company kept it closed for about ten years. It opened to the public in June 1998 and is part of the UNESCO site.

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